File managing method and data recorder using the same, data reproducing apparatus, data recording/reproducing apparatus, and disk recorded by the file managing method

ABSTRACT

A file management method for reducing a seek operation to a minimum even when a UDF file system is used is provided. The file management method has file management information for managing contiguous blocks on a disc as an extent and for grouping the extent as a file and managing the file, and includes the steps of: when creating a new directory on the disc, reserving as a reserved area for recording file management information on the file a file or a data area in the directory; and reserving a directory block having a predetermined size in the reserved area for recording a file entry of the directory and a file identifier descriptor of the directory.

TECHNICAL FIELD

[0001] The present invention relates to a file management methodsuitable for recording and reproducing AV data such as digital images,and a data recording apparatus, a data reproducing apparatus and a datarecording/reproducing apparatus using the method.

BACKGROUND ART

[0002] Recently, with development of high-density optical discs, theoptical discs have been used increasingly as recording media for digitalimages including moving images. The application fields of the opticaldiscs are so wide that they are utilized not only as peripheralequipment of a computer but also in a video player for home use. In thefuture, it is anticipated that the optical discs will be used asrecording media for video recording to replace tape media.

[0003] In order to deal with data in common in such a wide applicationarea, data is managed usually in the logical unit of a file. As one ofsuch file management methods, a file system in a format according to theUniversal Disk Format (UDF) specification is available.

[0004] The UDF specification acts to ensure the medium compatibilityamong various operating systems (OS) for computers, and also is employedin a DVD video player for consumer appliances. This specification is oneof the file formats that is expected to be applied in a wider variety ofplatforms in the future.

[0005] The following describes a file management method using a formataccording to the UDF specification, with reference to a drawing. FIG. 23shows an example of the construction of a data recording/reproducingapparatus to which a conventional file management method is applied.

[0006] In FIG. 23, numeral 101 denotes a disc such as an opticalmagnetic disc. Numeral 102 denotes a recording medium driving unit, andin the case of the disc 101 being an optical magnetic disc, this unit iscomposed of a spindle motor or the like. Numeral 103 denotes arecording/reproducing unit, and in the case of the disc 101 being anoptical magnetic disc, this unit is composed of an optical pickup, amagnetic head, a servo circuit, a modulation demodulation circuit andthe like.

[0007] In addition, numeral 104 denotes a memory unit, which stores datatemporarily at the time of recording/reproducing data. Numeral 105denotes a disc driving unit, and is composed of the disc 101, therecording medium driving unit 102, the recording/reproducing unit 103and the memory unit 104.

[0008] Further, numeral 106 denotes an AV signal processing unit, whichcarries out processing such as MPEG compression with respect to an AVinput signal input from a CCD camera or the like, and MPEG decompressionwith respect to AV data read from the disc 101 to output to a monitor orthe like. Numeral 107 denotes a system control unit, which controls theAV signal processing unit 106 and the disc driving unit 105.

[0009] In the data recording/reproducing apparatus constructed in thisway, at the time of recording data, an AV signal input into the AVsignal processing unit 106 is subjected to image compression processingaccording to the MPEG method or the like, and then is transferred to thememory unit 104 in the control of the system control unit 107.

[0010] Next, the recording medium driving unit 102 and therecording/reproducing unit 103 operate in the control of the systemcontrol unit 107 so that data in the memory unit 104 is recorded on thedisc 101.

[0011] At the time of reproducing data, the recording medium drivingunit 102 and the recording/reproducing unit 103 operate in the controlof the system control unit 107 so that data recorded in the disc 101 istransferred to the memory unit 104.

[0012] Next, in the control of the system control unit 107, data is readfrom the memory unit 104 and the AV signal processing unit 106 outputsthe data as an AV signal.

[0013] The following describes an example of a structure of the UDF filesystem that is a conventional file management method, with reference toa drawing. FIG. 24 shows a structure of a volume space of the UDFconstructed in the disc 101. In FIG. 24, in order to manage the disc 101as a logical volume, the disc 101 is divided into a unit called asector, and logical sector numbers (LSN) from 0 to the Last LSN areassigned to the sectors. Also, at the beginning and the termination ofthe volume space, volume structures are recorded. Further, between thesevolume structures, a partition space for recording structure informationon a file and a file as user data is allocated.

[0014] In the partition space, logical block numbers (LBN) from 0 to theLast LBN are assigned to each sector beginning from the leading sector.FIG. 25 shows the structure of the partition space when the directorystructure shown in FIG. 26 is recorded on the disc 101 (it should benoted that the following description refers to parameters specified inthe DVD-RAM standard).

[0015] In FIG. 26, a directory DIR1 is present under the ROOT directory,and FILE1_(—)1 and FILE1_(—)2 are present under the DIR1. In this state,in FIG. 25, a space bitmap descriptor is recorded at LBN=0 to 79.

[0016] The space bit map descriptor has a space bitmap indicatingwhether each logical block can be allocated or not. Each bit in thespace bitmap corresponds to each logical block, where this bit value of“1” means an unallocated state of the logical block, and “0” means anallocated state.

[0017] At LBN=80, a file set descriptor is recorded. In the file setdescriptor, location information on a file entry in the ROOT directoryis recorded. The file entry will be described later in detail.

[0018] At LBN=81, a terminating descriptor is recorded. The terminatingdescriptor represents a termination of the file set descriptor.

[0019] At LBN=82, the file entry of the ROOT directory is recorded. Thefile entry is used for storing various attribute information specific toeach file, information concerning a time stamp, a recorded location ofthe file, the size of the file and the like and for managing the file asa group of extents. The extent will be described later in detail.

[0020]FIG. 27 is an example of a structure of the file entry. In FIG.27, at a descriptor tag field, information for discriminating amongvarious descriptors such as a space bitmap descriptor, a file setdescriptor and a file entry in the partition space is recorded. In thecase of the file entry, it is specified to describe a value “261”. At aninformation control block (ICB) tag field, attribute informationconcerning the file entry itself is recorded. An extended attributefield is used for describing the attribute information other than thatspecified in the attribute information field in the file entry. At anallocation descriptor field, allocation descriptors are recorded in arequired number for managing a contiguous area of logical blocks as oneextent.

[0021]FIG. 28 shows a structure of the allocation descriptor. In theallocation descriptor, an extent is represented by the extent length andthe extent location.

[0022]FIG. 29 shows an interpretation on the upper 2 bits in the extentlength included in the allocation descriptor. The upper 2 bits representan allocation state and a recording state of the extent.

[0023] The value of “0” represents an allocated and recorded extent, anddata of the file is recorded. The value of “1” represents an allocatedand not recorded extent, and the area is allocated to a specificfile/directory but the data is not recorded therein. The value of “2”represents an unallocated and not recorded extent, where no data isrecorded. The value of “3” represents an extent continuing from theallocation descriptor. At the allocation descriptor field in a fileentry, a plurality of allocation descriptors can be recorded, so thatone file is constructed by a group of extents managed with theseallocation descriptors.

[0024] In the directory, a filename of a file included in the directoryand location information on the file entry are recorded. According tothe UDF, a directory is one type of files, and is recorded at LBN=83 andLBN=85 in FIG. 25.

[0025]FIG. 30 shows an example of a structure of the directory filerecorded at LBN=85. The directory file is constructed with a pluralityof file identifier descriptors, each of which has information concerningeach file included in the directory. Major information possessed by eachfile identifier descriptor is a filename of the corresponding file andlocation information on the file entry.

[0026] The following describes an operation where the datarecording/reproducing apparatus reads a desired file from a disc havingthe above-described UDF file system structure. FIG. 31 shows a logicalstructure of a directory/file in the file management informationconforming to the UDF specification.

[0027] In FIG. 31, a file set descriptor is recorded at a predeterminedlocation in the partition space as a part of the file managementinformation. In the file set descriptor, a recording location of a fileentry for a ROOT directory file is stored. In the file identifierdescriptor in the ROOT directory file, a recording location of a fileentry of a directory DIR1 is stored. In a file in the directory DIR1, aplurality of file identifier descriptors are present, each of whichstores filenames of FILE1_(—)1 and FILE1_(—)2 and recording locations oftheir file entries.

[0028] The following describes an operation for attempting to acquire arecording location of a target file from the hierarchical structureshown in FIG. 31. Here, it is assumed that the file FILE1_(—)1 is thetarget file.

[0029] Firstly, reference is made to a file set descriptor, from which alocation of the file entry of the ROOT directory is acquired.

[0030] Next, an allocation descriptor is read from the file entry, sothat the location and the length of the extent of the ROOT directoryfile are obtained, thus reading data of the ROOT directory file. Byscanning the thus obtained information on the ROOT directory file, afile identifier descriptor matching “DIR1”, which is the directory nameof the target, can be detected.

[0031] When the file identifier descriptor matching the target directoryis detected, then location information on the file entry is obtainedfrom the contents of the file identifier descriptor, while reading thefile entry.

[0032] Further, an allocation descriptor is read from such a file entry,so that the location and the length of the extent recorded in there areobtained, thus reading data on the directory file.

[0033] Then, by scanning the read data of the directory DIR1, a fileidentifier descriptor matching “FILE1_(—)1”, which is a filename of thetarget, is detected. When the file identifier descriptor matching thetarget directory is detected, then location information on the fileentry is obtained from such a file identifier descriptor, while readingthe file entry.

[0034] Finally, an allocation descriptor is read from the file entry, sothat the location and the length of the extent recorded in there areobtained, thus reading data of the FILE1_(—)1 as the target file.

[0035] Next, the following describes an operation where the datarecording/reproducing apparatus records data on a disc having astructure according to the UDF file system. The following descriptiondeals with a case where FILE1_(—)3 is recorded further under thedirectory DIR1 with respect to a disc having the partition space shownin FIG. 32.

[0036] Firstly, a space bitmap is scanned so that a logical block havinga bit value of “1” indicating an unallocated state is obtained. Withrespect to the unallocated state logical block, data of the FILE1_(—)3is recorded as an extent. When the recording of the extent is completed,then a file entry indicating the FILE1_(—)3 is recorded with respect tothe unallocated logical block.

[0037] In this step, location information and a length of the extentindicating the FILE1_(—)3 are recorded in the file entry as allocationdescriptors in a required number. In a file of the directory DIR1 as aparent directory of the FILE1_(—)3, a file identifier descriptorindicating the FILE1_(—)3 is recorded.

[0038] In this file identifier descriptor, a filename of the FILE1_(—)3and location information of the file entry are recorded. Then, a bit inthe space bitmap corresponding to the sector that was allocated as aresult of the above process is set at 0, which indicates an allocatedstate.

[0039] As a result of the above-described process, the logical volumespace becomes as shown in FIG. X10. It should be noted that the order ofthe processing for dealing with the file management information is notlimited especially to the above-described example, but a process in theother orders may be carried out.

[0040] However, the above-described file management method using the UDFspecification has the following problems.

[0041] First, according to the UDF specification, a directory isrecorded in a partition space as a file, and a file entry also isrecorded in the partition space. Therefore, the directory file and fileentry might be arranged in a dispersed manner on the disc.

[0042] Thus, in the case of attempting to read all files existing undera directory, if a directory file and a file entry are arranged in adispersed manner, a seek operation with respect to the disc would begenerated frequently.

[0043] For example, in FIG. 32 also, each of the file entries ofFILE1_(—)1, FILE1_(—)2 and FILE1_(—)3 are arranged in a dispersedmanner, so that a seek operation is essential for reading these fileentries. In such a situation, if a file to be reproduced is a file thatrequires real time reproduction, such as an AV file, the frequent seekoperation would make smooth reproduction difficult.

[0044] Similarly, if real time recording is required as in the case ofan AV file or the like, when recording the file entry after AV dataitself is recorded, a seek operation would be generated with respect tothe disc, which interrupts the AV data recording during the seekoperation.

[0045] In addition, at the time of activating the apparatus, it can beconsidered that the number of seek operations with respect to the disccan be reduced by performing an on-memory processing by reading all filemanagement information into a memory. However, a lot of seek operationsare generated in such a process also, and therefore it would take a longtime to activate the apparatus itself. Furthermore, since it isdifficult to estimate the required memory capacity in advance, anarchitecture of a system for arranging computing resources efficientlyalso becomes difficult.

DISCLOSURE OF THE INVENTION

[0046] In order to cope with the above-stated problems, the object ofthe present invention is to provide a file management method in which aseek operation can be reduced to a minimum even when a UDF file systemis used.

[0047] To fulfill the above-stated object, a file management methodaccording to the present invention has file management information formanaging contiguous blocks on a disc as an extent and for grouping theextent as a file and managing the file, and the file management methodincludes the steps of: when creating a new directory on the disc,reserving as a reserved area for recording file management informationon the file a file or a data area in the directory; and recordinginformation concerning an operation condition of the file managementinformation in the reserved area, in addition to management informationon the directory and the file.

[0048] With this configuration, there is no need to write file attributeinformation and a file entry into the disc every time a file is created,and therefore the number of seek operations can be reducedsignificantly. As a result, AV data as mass data requiring a real timeoperation can be recorded and reproduced securely.

[0049] In the aforementioned file management method of the presentinvention, it is preferable that, when the file management informationrecorded in the reserved area is updated, information indicating a factthat the file management information has been updated is recorded in thereserved area. This is because, based on whether the file managementinformation is updated or not, judgment as to whether attributeinformation needs to be written back can be made easily, and thereforean unnecessary seek operation generated when the information has notbeen rewritten can be avoided.

[0050] In the aforementioned file management method of the presentinvention, it is preferable that a leading location block and an endinglocation block of the reserved area on the disc are recorded in thereserved area. This is because a location for writing at the time ofstarting recording can be specified easily by referring to the leadinglocation block and the ending location block of the reserved area.Therefore, an unnecessary seek operation for searching a writinglocation can be avoided.

[0051] In the aforementioned file management method of the presentinvention, it is preferable that a leading location block of an area fora file entry in the reserved area and a leading location block of anarea for file attribute information in the reserved area are recorded inthe reserved area. This is because a location for writing at the time ofstarting recording can be specified easily by referring to the leadinglocation block of an area for a file entry and the leading locationblock of an area for file attribute information in the reserved area.Therefore, an unnecessary seek operation can be avoided.

[0052] In the aforementioned file management method of the presentinvention, it is preferable that a time when the file managementinformation is last updated is recorded in the reserved area. This isbecause writing of an AV file into a medium onto which the AV fileshould be recorded can be judged easily by recording the last updateddate and time in the file management information and making acomparison.

[0053] In the aforementioned file management method of the presentinvention, it is preferable that the reserved area is divided into Nareas (N is a natural number no less than 2), at least one of thedivided areas is allocated to an area for a file entry, and at least oneof the divided areas is allocated to an area for file attributeinformation. This is because a location for writing at the time ofstarting recording can be specified easily, and therefore an unnecessaryseek operation can be avoided.

[0054] Next, to fulfill the above-stated object, another file managementmethod according to the present invention has file managementinformation for managing contiguous blocks on a disc as an extent andfor grouping the extent as a file and managing the file, and the filemanagement method includes the steps of: when creating a new directoryon the disc, reserving as a reserved area for recording file managementinformation on the file a file or a data area in the directory; andreserving a directory block having a predetermined size in the reservedarea for recording a file entry of the directory and a file identifierdescriptor of the directory.

[0055] With this configuration, the file entry of the directory and thefile identifier descriptor of the director can be recorded together inthe directory block having the predetermined size. Therefore, a seekoperation can be reduced during a procedure such as adding and rewritinga file in a specific directory, so that recording and reproducing of afile requiring a real time property such as an AV file can be conductedeasily.

[0056] In the aforementioned file management method of the presentinvention, it is preferable that an area is reserved as a directoryblock group in a size of an arbitrary integral multiple of a size of thedirectory block. This is because the directory block group can be usedefficiently without waste.

[0057] In the aforementioned file management method of the presentinvention, it is preferable that the size of the directory block groupis in the unit of error correction. This is because the smallest unit inrewriting coincides with the unit of error correction, and thereforeread-modify-write can be completed in one block, which enables speedyrewriting. Furthermore, even when a disc has to be exchanged because ofa defect or the like, the continuity of data can be insured.

[0058] In the aforementioned file management method of the presentinvention, it is preferable that concurrently with the process ofreserving the directory block group, an area for recording for a fileentry, which corresponds to a required area for recording the file whosefile identifier descriptor can be described in the directory, and a partor all of the file is reserved in the reserved area initially and at onetime. This is because a seek operation can be reduced further byrecording a file entry and file attribute information together as forthe file in a specific directory.

[0059] In the aforementioned file management method of the presentinvention, it is preferable that an area is reserved as a directory areain a size of an arbitrary integral multiple of a size of the directoryblock group. This is because the directory area can be used efficientlywithout waste and a file entry or the like can be recorded by groupingit according to a predetermined specification, which further can reducea seek operation.

[0060] In the aforementioned file management method of the presentinvention, it is preferable that concurrently with the process ofreserving the directory area, an area for recording for a file entry,which corresponds to a required area for recording the file whose fileidentifier descriptor can be described in the directory, and a part orall of the file is reserved in the reserved area initially and at onetime. This is because a file entry or the like of the file in a specificdirectory can be recorded at one time, and therefore a seek operationfurther can be reduced.

[0061] In the aforementioned file management method of the presentinvention, it is preferable that at the same time an area correspondingto the directory block group is reserved beforehand. This is because anew directory block group can be reserved at a predetermined location,and therefore a seek operation further can be reduced.

[0062] In the aforementioned file management method of the presentinvention, it is preferable that when creating a new file, the directoryblock is created newly at the end of the reserved directory block.

[0063] In the aforementioned file management method of the presentinvention, it is preferable that when, in the reserved directory blockgroup, any one of the area for information concerning the fileidentifier descriptor in the directory and the reserved area forrecording the file entry and the part or all of the file becomesinsufficient and when a new file further is created, the directory blockis created newly at the end of the reserved directory block, and at thesame time an area for recording for a file entry, which corresponds to arequired area for recording the file whose file identifier descriptorcan be described in the directory, and a part or all of the file isreserved in the reserved area at one time. This is because even when anoperation such as adding a new file is performed in the case of theshortage of a sufficient not-registered area for recording, a seekoperation can be reduced to a minimum.

[0064] In the aforementioned file management method of the presentinvention, it is preferable that when creating a new file, the directoryblock group is created newly at the area reserved beforehand as thedirectory block group. This is because a seek operation can be within adesigned range.

[0065] In the aforementioned file management method of the presentinvention, it is preferable that when, in the reserved directory blockgroup, any one of the area for information concerning the fileidentifier descriptor in the directory and the reserved area forrecording the file entry and the part or all of the file becomesinsufficient and when a new file further is created, the directory blockgroup is created newly at the area reserved beforehand as the directoryblock group, and at the same time an area for recording for a fileentry, which corresponds to a required area for recording the file whosefile identifier descriptor can be described in the directory, and a partor all of the file is reserved in the reserved area at one time. This isbecause, when a file entry or the like is recorded by classifying itaccording to a prescribed specification, and even when a sufficientnot-registered area for recording is exhausted and a procedure such asadding a new file is conducted, a seek operation can be reduced to aminimum.

[0066] In the aforementioned file management method of the presentinvention, it is preferable that wherein when creating a new file, thedirectory block group is created newly in the reserved area. This is forusing the reserved area effectively.

[0067] In the aforementioned file management method of the presentinvention, it is preferable that when, in the reserved directory blockgroup, any one of the area for information concerning the fileidentifier descriptor in the directory and the reserved area forrecording the file entry and the part or all of the file becomesinsufficient, and the area reserved beforehand as the directory blockgroup also becomes insufficient, and when a new file is created, thedirectory block group is created newly in the reserved area, and at thesame time an area for recording for a file entry, which corresponds to arequired area for recording the file whose file identifier descriptorcan be described in the directory, and a part or all of the file isreserved in the reserved area at one time. This is because a reservedarea is used effectively, so that even when there is no sufficientnot-registered area for recording and an operation such as adding a newfile is conducted, a seek operation can be reduced to a minimum.

[0068] In the aforementioned file management method of the presentinvention, it is preferable that when creating a new file, the reservedarea is reserved newly in a space area of the disc, and the directoryblock group is created in the thus prepared reserved area. This isbecause, even when there is no space area in the reserved area, the sameeffects as in utilizing the reserved area can be expected by using thespace area of the disc.

[0069] In the aforementioned file management method of the presentinvention, it is preferable that, when, in the reserved directory blockgroup, the area for recording the file identifier descriptor in thedirectory becomes insufficient, the area reserved beforehand as thedirectory block become insufficient, and an area for reservation isinsufficient in the reserved area that has been reserved initially, andwhen a new file is created, the reserved area is reserved newly in aspace area of the disc, the directory block group is created in the thusprepared reserved area, and at the same time an area for recording for afile entry, which corresponds to a required area for recording the filewhose file identifier descriptor can be described in the directory, anda part or all of the file is reserved in the thus prepared reserved areaat one time. This is because, even when there is no space area in thereserved area, and when there is no sufficient not-registered area forrecording and a procedure such as adding a new file is conducted, a seekoperation can be reduced to a minimum by utilizing the space area of thedisc.

[0070] Next, to fulfill the above-stated object, a data recordingapparatus, a data reproducing apparatus, and a datarecording/reproducing apparatus according to the present inventionrecord and reproduce data by the above-described file managementmethods.

[0071] With this configuration, there is no need to write file attributeinformation and a file entry onto a disc every time a file is created,and therefore the number of seek operations can be decreasedsignificantly. As a result, a data recording apparatus, a datareproduction apparatus, and a data recording/reproducing apparatus bywhich AV data can be recorded and reproduced as mass data requiring thereal time reproduction can be realized.

BRIEF DESCRIPTION OF DRAWINGS

[0072]FIG. 1 shows a configuration example of a datarecording/reproducing apparatus using a file management method accordingto Embodiment 1 of the present invention.

[0073]FIG. 2 shows an example of a structure of the initial directory inthe file management method according to Embodiment 1 of the presentinvention.

[0074]FIG. 3 shows an example of a structure of the initial partitionspace in the file management method according to Embodiment 1 of thepresent invention.

[0075]FIG. 4A shows an example of a structure of a recording area offile management information in the file management method according toEmbodiment 1 of the present invention, and FIG. 4B shows an example of astructure of a block map in the recording area of the file managementinformation in the file management method according to Embodiment 1 ofthe present invention

[0076]FIG. 5 is a flowchart showing a procedure for recording an AV filein the file management method according to Embodiment 1 of the presentinvention.

[0077]FIG. 6 is another flowchart showing a procedure for recording anAV file in the file management method according to Embodiment 1 of thepresent invention.

[0078]FIG. 7 shows an example of a structure of the partition spaceafter an AV file is recorded in the file management method according toEmbodiment 1 of the present invention.

[0079]FIG. 8 shows an example of a structure of the initial partitionspace in the file management method according to Embodiment 6 of thepresent invention.

[0080]FIG. 9A shows an example of a structure of a recording area offile management information in the file management method according toEmbodiment 1 of the present invention, and FIG. 9B shows an example of astructure of a block map in the recording area of the file managementinformation in the file management method according to Embodiment 1 ofthe present invention.

[0081]FIG. 10 shows an example of a structure of the partition spaceafter an AV file is recorded in the file management method according toEmbodiment 6 of the present invention.

[0082]FIG. 11 shows an example of a structure of the initial directoryin the file management method according to Embodiment 7 of the presentinvention.

[0083]FIG. 12 shows an example of a structure of the initial partitionspace in the file management method according to Embodiment 7 of thepresent invention.

[0084]FIG. 13 shows an example of a structure of the directory in thefile management method according to Embodiment 7 of the presentinvention.

[0085]FIG. 14 shows a structure of the initial partition space in thefile management method according to Embodiment 9 of the presentinvention.

[0086]FIG. 15 shows a structure of the initial partition space in thefile management method according to Embodiment 10 of the presentinvention.

[0087]FIG. 16 shows a structure of the initial partition space in thefile management method according to Embodiment 12 of the presentinvention.

[0088]FIG. 17 shows a structure of the initial partition space in thefile management method according to Embodiment 13 of the presentinvention.

[0089]FIG. 18 shows a structure of the partition space after recordingin the file management method according to Embodiment 13 of the presentinvention.

[0090]FIG. 19 shows a structure of the initial partition space in thefile management method according to Embodiment 14 of the presentinvention.

[0091]FIG. 20 shows a structure of the partition space after recordingin the file management method according to Embodiment 14 of the presentinvention.

[0092]FIG. 21 shows a structure of the initial partition space in thefile management method according to Embodiment 15 of the presentinvention.

[0093]FIG. 22 shows a structure of the partition space after recordingin the file management method according to Embodiment 15 of the presentinvention.

[0094]FIG. 23 shows a configuration example of a datarecording/reproducing apparatus using the conventional file managementmethod.

[0095]FIG. 24 shows an example of a structure of the volume space in thedata recording/reproducing apparatus using the conventional filemanagement method.

[0096]FIG. 25 shows an example of the partition space in the datarecording/reproducing apparatus using the conventional file managementmethod.

[0097]FIG. 26 shows an example of a directory structure in the datarecording/reproducing apparatus using the conventional file managementmethod.

[0098]FIG. 27 shows an example of a file entry in the datarecording/reproducing apparatus using the conventional file managementmethod.

[0099]FIG. 28 shows an example of an allocation descriptor in the datarecording/reproducing apparatus using the conventional file managementmethod.

[0100]FIG. 29 shows interpretations and explanations of the extentlength in the data recording/reproducing apparatus using theconventional file management method.

[0101]FIG. 30 shows an example of a structure of the directory file inthe data recording/reproducing apparatus using the conventional filemanagement method.

[0102]FIG. 31 shows an example of the hierarchical structure of a filein the data recording/reproducing apparatus using the conventional filemanagement method.

[0103]FIG. 32 shows an example of a structure of the partition spaceafter recording in the data recording/reproducing apparatus using theconventional file management method.

BEST MODE FOR CARRYING OUT THE INVENTION

[0104] The following describes a file management method according toembodiments of the present invention, with reference to the drawings.Hereinafter, a file containing audio data and visual data compressedaccording to the MPEG method or the like will be referred to as an AVfile. In addition, in this specification, a disc means a generalrecording medium having a disc-shape, including an optical disc such asDVD-RAM, MO, DVD-R, DVD-RW and DVD+RW, and a hard disc.

[0105] Embodiment 1

[0106] First, FIG. 1 shows a configuration example of a datarecording/reproducing apparatus to which a file management methodaccording to Embodiment 1 of the present invention is applied. Numeral 1denotes a disc such as optical magnetic disc, and numeral 2 denotes arecording medium driving unit, respectively. In the case of the disc 1being an optical magnetic disc, the recording medium driving unit 2 iscomposed of a spindle motor and the like.

[0107] Numeral 3 denotes a recording/reproducing unit, and in the caseof the disc 1 being an optical magnetic disc, this unit is composed ofan optical pickup, a magnetic head, a servo circuit, a modulationdemodulation circuit and the like.

[0108] In addition, numeral 4 denotes a memory unit, which stores datatemporarily at the time of recording/reproducing data. Numeral 5 denotesa disc driving unit, and is composed of the disc 1, the recording mediumdriving unit 2, the recording/reproducing unit 3 and the memory unit 4.

[0109] Further, numeral 6 denotes an AV signal processing unit, whichcarries out processing such as MPEG compression with respect to an AVinput signal input from a CCD camera or the like, and MPEG decompressionwith respect to AV data read from a disc medium to output to a monitoror the like. Numeral 7 denotes a system control unit, which controls theAV signal processing unit 6 and the disc driving unit 5.

[0110] In the data recording/reproducing apparatus constructed in thisway, at the time of recording data, an AV signal input into the AVsignal processing unit 6 is subjected to image compression processingaccording to the MPEG method or the like, and then is transferred to thememory unit 4 in the control of the system control unit 7. Next, therecording medium driving unit 2 and the recording/reproducing unit 3operate in the control of the system control unit 7 so that the data inthe memory unit 4 is recorded on the disc 1.

[0111] At the time of reproducing data, the recording medium drivingunit 2 and the recording/reproducing unit 3 operate in the control ofthe system control unit 7 so that data recorded in the disc 1 istransferred to the memory unit 4. Next, in the control of the systemcontrol unit 7, the data is read from the memory unit 4 and the AVsignal processing unit 6 outputs the data as an AV signal.

[0112]FIG. 2 shows an example of a file/directory structure immediatelyafter a directory is formed for recording an AV file in the filemanagement method according to Embodiment 1. In FIG. 2, ROOT surroundedby an oval indicates a root directory, and AV_DIR1 indicates a directoryfor recording an AV file therein, respectively. AVFILES.IFO surroundedby a rectangle indicates a management file created in the directoryAV_DIR1.

[0113]FIG. 3 shows an example of a data structure of the partition spacein a state where the file/directory structure shown in FIG. 2 isrecorded on the disc 1 used in the data recording/reproducing apparatusto which the file management method according to Embodiment 1 of thepresent invention is applied. In FIG. 3, at LBN=0 to 79, a space bitmapdescriptor is recorded. Since LBN=251 or later becomes an “unallocatedstate”, each bit corresponding to these sectors is set at “1”.

[0114] In addition, at LBN=80, a file set descriptor is recorded. Itshould be noted that if the file entry is a file entry of the rootdirectory, location information on such a file entry is recorded in thefile set descriptor. At LBN=81, a terminating descriptor is recorded.

[0115] Further, at LBN=82, a file entry of the ROOT directory isrecorded, at LBN=83, a file identifier descriptor of the ROOT directoryas a parent directory and a file identifier descriptor of the directoryAV_DIR1 are recorded, and at LBN=84, a file entry of the directoryAV_DIR1 is recorded, respectively.

[0116] Next, at LBN=85, a file identifier descriptor of the directoryAV_DIR1 as a parent directory and a file identifier descriptor of theAVFILES.IFO file are recorded. At LBN=86, a file entry of theAVFILES.IFO file is recorded. At LBN=87, a management area of theAVFILES.IFO is recorded.

[0117] The management area of the AVFILES.IFO has a configuration shownin FIG. 4A, where a block map shown in FIG. 4B is recorded. Here, theblock map is a map for managing an operation condition of each LBN atLBN=88 to 250. The LBN=88 to 250 is an extent of the AVFILES.IFO file,where the value of the upper 2 bits of the allocation descriptor is setso that the extent becomes “allocated” and “not recorded”.

[0118] Therefore, in the operation of the conventional file system, datacannot be written at LBN=87 to 250. Hereinafter, this extent of theAVFILES.IFO file will be called an AV reserved area. Since LBN=0 to 250are in a state of “allocated” as described above, a corresponding bit inthe space bitmap is set at “0”.

[0119] When recording an AV file on a disc in such a state, a procedurein a flowchart shown in FIG. 5 is carried out. After commencingrecording of the AV file according to a user's instruction or the like,as the first step in FIG. 5, contents of LBN=0 to 250 on the disc 1 areread into the memory unit 4 (Step S501). Next, by scanning informationof the AV reserved area on the memory unit 4, the presence or absence ofa not recorded area required for newly recording file attributeinformation and a file entry is judged (Step S502). If judged as theabsence of a sufficient not recorded area for newly recording (StepS502: No), then error handling is carried out and the AV file recordingprocess is completed. If judged as the presence of a sufficientnot-recording area, the file attribute information and the file entryare recorded in the not recorded area in the AV reserved area on thememory unit 4 (Step S503).

[0120] In this step, the recording of the file attribute information andthe file entry changes the size of the extent of the directory AV_DIR1and the size of the AVFILES.IFO file. Therefore, based on such a change,an allocation descriptor of the file entry of the directory AV_DIR1 andthe file entry of the AVFILES.IFO file are rewritten.

[0121] Next, by scanning the space bitmap on the memory unit 4, thepresence or absence of unrecorded contiguous logical blocks and in anumber required for recording the AV file is judged (Step S504). Ifjudged as the absence of the contiguous unrecorded logical blocks and inthe required number (Step S504: No), then error handling is carried outand the AV file recording process is completed. If judged as thepresence, data is recorded with respect to the logical blocks on thedisc, which correspond to the not recorded area obtained in the StepS504 (Step S505).

[0122] When the recording of the AV file data is completed, informationconcerning the location and the length of the extent of the AV file isrecorded in the allocation descriptor in the file entry on the memoryunit 4, which was created in Step S503, so as to update the filemanagement information of the AV file (Step S506). Also, requiredinformation such as a filename and a file creation time is updated withrespect to the file attribute information and the file entry, inaddition to the allocation descriptor. At the same time, the contents ofthe block map in the AVFILES.IFO file are rewritten based on such achange.

[0123] Next, the bits of the space bitmap on the memory unit 4corresponding to the logical blocks onto which data was recorded in StepS504 are changed to “0” that represents an “allocated” state (StepS507). Then, the contents of the memory unit 4 are written back to thelocation at LBN=0 to 250 (Step S508). In this way, the file is recorded,which means that the AV file is recorded under the directory AV_DIR1.

[0124] In the case of attempting to record a plurality of AV filessequentially, after Step S601 in a flowchart shown in FIG. 6, Step S602through step S607 may be repeated until all of the AV files have beenrecorded, and after all of the AV files have been recorded, theprocedure may go to Step S608. In this case also, in Step S605 where thefile entry and the file attribute information in the extent of theAVFILES.IFO file are added, judgment as to whether the area has beenused already or not is carried out by utilizing the block map in theAVFILES.IFO file.

[0125] As stated above, according to Embodiment 1, there is no need towrite file attribute information and a file entry onto a disc every timea file is created, and therefore the number of seek operations can bedecreased significantly. As a result, AV data as mass data requiring thereal time reproduction can be recorded and reproduced.

[0126] After FILE1.DAT and FILE2.DAT as AV files are recorded under thedirectory AV_DIR1 in accordance with the procedure shown in theflowchart in FIG. 5, a data structure of the partition space becomes asshown in FIG. 7.

[0127] In FIG. 7, among the AV reserved areas, a logical block with alarger LBN is used for recording a new file entry. Meanwhile, fileattribute information is recorded so as to be appended to the“allocated” and “not recorded” extent of the AVFILES.IFO as a managementfile.

[0128] Since file identifier descriptors and file entries both have avariable length data structure, it is preferable that file identifierdescriptors are recorded at LBN with a smaller number in the AV reservedarea, while file entries are recorded at LBN with a larger number asdescribed above.

[0129] This is because, when adding a file entry and file attributeinformation into the extent of the AVFILES.IFO file, judgment concerninga space area can be carried out easily by referring to the block map inthe AVFILES.IFO file.

[0130] It should be noted that the recording procedure is not limited tothe procedure shown in FIG. 5, but the following procedure may beconducted: that is, as described in International Publication No.WO98/14938 as one example, a plurality of contiguous space areas arereserved prior to actual data recording and are registered as an“allocated state” in the space bitmap, and then actual data recording isstarted.

[0131] In addition, the allocation descriptor of the directory AV_DIR1and the information on the space bitmap may be updated at one time afterthe recording of file data is completed.

[0132] A procedure for making the data structure in the partition spaceof the disc the initial state shown in FIG. 3 is carried out whennecessary, prior to the recording of the AV file.

[0133] The name of the directory/file into which the AV file is recordedis not limited to that stated in Embodiment 1, but other directory/filenames also are acceptable.

[0134] In this embodiment, contents of LBN=0 to 250 are read into thememory unit 4 at the time of recording and reproducing. However, thereis no need to keep all information in the memory unit 4, but onlyinformation necessary for the recording/reproducing operation is kept,and only information that needs to be updated may be written back to thedisc 1.

[0135] In this embodiment, LBN=87 to 250 is made the “allocated” and“not recorded” extent of the AVFILES.IFO file as the AV reserved area,but the recording location and capacity of the AV reserved area are notlimited to LBN=0 to 250. Insofar as reserving a contiguous area on thedisc, other recording locations and capacities also are acceptable.

[0136] Embodiment 2

[0137] The following describes a file management method according toEmbodiment 2 of the present invention, with reference to the drawings.In the above-stated Embodiment 1, a block map is recorded in amanagement area of the AVFILES.IFO file. On the other hand, Embodiment 2has a feature in that a changed-state indication flag concerning allattribute information including a reserved area is recorded, in additionto the block map.

[0138] That is, at LBN=87, a management area of the AVFILES.IFO file isrecorded. The management area of the AVFILES.IFO has a configurationshown in FIG. 4A, onto which a changed-state indication flag concerningall attribute information including the reserved area is recorded. Notehere that the changed-state indication flag indicates whether any one ofLBN=87 to 250 is rewritten or not.

[0139] A basic procedure for recording an AV file on a disc using thechanged-state indication flag concerning all attribute informationincluding a reserved area is similar to the procedure shown in FIG. 5.However, the bits of the space bitmap on the memory unit 4 correspondingto the logical blocks onto which data was recorded in Step S504 arechanged to “0”, which represents “allocated” (Step S507), and at thesame time the changed-state indication flag in the AVFILES.IFO file alsois changed because the attribute information is rewritten.

[0140] Then, when confirming the contents of the changed-stateindication flag in the AVFILES.IFO file, if the flag indicates that theattribute information is rewritten, then the contents of the memory unit4 are written back to the location at LBN=0 to 250 on the disc 1. If theattribute information is not rewritten, a procedure of writing back isnot carried out (Step S508). In this way, the file is recorded, whichmeans that the AV file is recorded under the directory AV_DIR1.

[0141] In the case of attempting to record a plurality of AV filessequentially, after Step S601 in the flowchart shown in FIG. 6, StepS602 through step S607 may be repeated until all of the AV files havebeen recorded, and after all of the AV files have been recorded, theprocedure may go to Step S608. In this case also, in Step S608, thecontents of the changed-state indication flag are confirmed and if theflag indicates that the attribute information is rewritten, then thecontents of the memory unit 4 are written back to the location at LBN=0to 250 on the disc 1. If the attribute information is not rewritten, aprocedure for writing back is not carried out.

[0142] As stated above, according to Embodiment 2, judgment as towhether the attribute information needs to be written back or not can becarried out easily on the basis of the changed-state indication flag inthe AVFILES.IFO file. Therefore, an unnecessary seek operation generatedwhen the information is not rewritten can be avoided.

[0143] Embodiment 3

[0144] The following describes a file management method according toEmbodiment 3 of the present invention, with reference to the drawings.In Embodiment 1, a block map is recorded in a management area of theAVFILES.IFO file. On the other hand, Embodiment 3 has a feature in thata starting LBN and an ending LBN of a reserved area are recorded inaddition to the block map.

[0145] That is, at LBN=87, a management area of the AVFILES.IFO file isrecorded. The management area of the AVFILES.IFO file has aconfiguration shown in FIG. 4A, and the starting LBN and the ending LBNof the reserved area are recorded. Note here that, in the case ofEmbodiment 3, the starting LBN and the ending LBN of the reserved areacorrespond to a starting LBN=87 of the reserved area and an endingLBN=250 of the reserved area, respectively.

[0146] A basic procedure for recording an AV file on a disc using thestarting LBN and the ending LBN of the reserved area is similar to theprocedure shown in the flowchart in FIG. 5.

[0147] When file attribute information and a file entry are recorded inthe not recorded area in the AV reserved area on the memory unit 4 (StepS503), the file attribute information is recorded from LBN=87 byreferring to the starting LBN in the management area of the AVFILES.IFOand similarly the file entry is recorded from LBN=250 by referring tothe ending LBN of the reserved area.

[0148] When all the procedure is completed, the contents of the memoryunit 4 are written back to the location at LBN=0 to 250 on the disc 1.In this way, the file is recorded, which means that the AV file isrecorded under the directory AV_DIR1.

[0149] As described above, according to Embodiment 3, a location forwriting at the time of starting recording can be specified easily byreferring to the starting LBN and the ending LBN of the reserved area.Therefore, an unnecessary seek operation for searching a writinglocation can be avoided.

[0150] Embodiment 4

[0151] The following describes a file management method according toEmbodiment 4 of the present invention, with reference to the drawings.In Embodiment 1, a block map is recorded in a management area of theAVFILES.IFO file. On the other hand, Embodiment 4 has a feature in thata leading location LBN of a file entry area and a leading location LBNof a file attribute information area are recorded in addition to theblock map.

[0152] That is, at LBN=87, a management area of the AVFILES.IFO file isrecorded. The management area of the AVFILES.IFO file has aconfiguration shown in FIG. 4A, and the leading location LBN of the fileentry area and the leading location LBN of the file attributeinformation area are recorded. Note here that, in the case of Embodiment4, the leading location LBN of the file entry area and the leadinglocation LBN of the file attribute information area correspond to aleading location LBN=250 of the file entry area and a leading locationLBN=87 of the file attribute information area, respectively.

[0153] A basic procedure for recording an AV file on a disc using theleading location LBN of the file entry area and the leading location LBNof the file attribute information area is similar to the procedure shownin the flowchart in FIG. 5.

[0154] When file attribute information and a file entry are recorded inthe not recorded area in the AV reserved area on the memory unit 4 (StepS503), the file entry is recorded from LBN=250 by referring to theleading location LBN of the file entry area in the management area ofthe AVFILES.IFO, and similarly the file attribute information isrecorded from LBN=87 by referring to the leading location LBN of thefile attribute information area.

[0155] Then, the bits of the space bitmap on the memory unit 4corresponding to the logical blocks onto which data was recorded in StepS504 are changed to “0” that represents “allocated” (Step S507).

[0156] When all the procedure is completed, the contents of the memoryunit 4 are written back to the location at LBN=0 to 250 on the disc 1.In this way, the file is recorded, which means that the AV file isrecorded under the directory AV_DIR1.

[0157] As described above, according to Embodiment 4, a location forwriting at the time of starting recording can be specified easily byreferring to the leading location LBN of the file entry area and theleading location LBN of the file attribute information area. Therefore,an unnecessary seek operation can be avoided.

[0158] Embodiment 5

[0159] The following describes a file management method according toEmbodiment 5 of the present invention, with reference to the drawings.In Embodiment 1, a block map is recorded in a management area of theAVFILES.IFO file. On the other hand, Embodiment 5 has a feature in thata last updated date and time are recorded in addition to the block map.

[0160] That is, at LBN=87, a management area of the AVFILES.IFO file isrecorded. The management area of the AVFILES.IFO file has aconfiguration shown in FIG. 4A, and the last updated date and time arerecorded. Note here that the last updated date and time are the date andtime when the AVFILES.IFO file is rewritten.

[0161] A basic procedure for recording an AV file on a disc using thelast updated date and time is similar to the procedure shown in theflowchart in FIG. 5.

[0162] When file attribute information and a file entry are recorded inthe not recorded area in the AV reserved area on the memory unit 4 (StepS503), the recording of the file attribute information and the fileentry changes the size of the extent of the directory AV_DIR1 and thesize of the AVFILES.IFO file. Therefore, based on such a change, anallocation descriptor of the file entry of the directory AV_DIR1 and thefile entry of the AVFILES.IFO file are rewritten.

[0163] Also, required information such as a filename and a file creationtime is updated with respect to the file attribute information and thefile entry, in addition to the allocation descriptor. At the same time,the last updated date and time in the AVFILES.IFO file are updated tothe latest date and time to be recorded.

[0164] When all the procedure is completed, the contents of the memoryunit 4 are written back to the location at LBN=0 to 250 on the disc 1.In this way, the file is recorded, which means that the AV file isrecorded under the directory AV_DIR1.

[0165] Inherently, recording of an AV file is followed by rewriting of amanagement area of the AVFILES.IFO file. Therefore, the last updatedinformation provided in the file entry of each recorded AV file and thelast updated date and time in the AVFILES.IFO file always agree witheach other.

[0166] However, in the case where a file is written with anotherrecording apparatus by a method different from Embodiment 5, rewritingof the management area of the AVFILES.IFO file is not generated. In thiscase, since the last updated information provided in each of the fileentries and the last updated date and time in the AVFILES.IFO file donot agree with each other, it can be found that a procedure other thanthe recording of an AV file is carried out.

[0167] As stated above, according to Embodiment 5, writing of an AV fileinto a medium onto which the AV file should be recorded can be judgedeasily by recording the last updated date and time in the managementarea of the AVFILES.IFO file and making a comparison. Therefore, anunnecessary seek operation can be avoided at the time of recording an AVfile.

[0168] Embodiment 6

[0169] The following describes a file management method according toEmbodiment 6 of the present invention, with reference to the drawings.In Embodiment 1, a block map is recorded in a management area of theAVFILES.IFO file. On the other hand, Embodiment 6 has a feature in that,in addition to the foregoing, the management area is divided into pluralareas, at least one of the divided management areas is allocated torecord a file entry, and at least one of them is allocated to record afile attribute information.

[0170]FIG. 8 shows an example of a data structure in the initialpartition space of a disc used in a data recording/reproducing apparatusto which a file management method according to Embodiment 6 of thepresent invention is applied. In FIG. 8, at LBN=0 to 79, a space bitmapdescriptor is recorded. Since LBN=251 or later becomes an “unallocatedstate”, each bit corresponding to these sectors is set at “1”.

[0171] As shown in FIG. 8, a not recorded area in the AV reserved areaat LBN=88 to 250 is divided into two areas of LBN=88 to 169 and LBN=170to 250. Then, these two areas are allocated as a file entry area and afile attribute information area, respectively.

[0172] At LBN=87, the management area of the AVFILES.IFO file isrecorded. The management area of the AVFILES.IFO file has aconfiguration shown in FIGS. 9A and 9B, and a leading location LBN ofthe allocated file entry area and a leading location LBN of theallocated file attribute information area are recorded. Note here that,in Embodiment 6, the leading location LBN of the file entry area and theleading location LBN of the file attribute information area correspondto the leading location LBN=170 of the file entry area and the leadinglocation LBN=87 of the file attribute information area, respectively.

[0173] When recording an AV file on a disc in such a state, theprocedure shown in the flowchart of FIG. 5 is carried out. First,contents of LBN=0 to 250 on the disc 1 are read into the memory unit 4(Step S501). Next, by scanning information of the AV reserved area onthe memory unit 4, the presence or absence of a not recorded arearequired for newly recording file attribute information and a file entryis judged (Step S502). If judged as the absence of a sufficient notrecorded area for newly recording (Step S502: No), then error handlingis carried out and the AV file recording process is completed. If judgedas the presence of a sufficient not-recording area, the file attributeinformation and the file entry are recorded in the not recorded area inthe AV reserved area on the memory unit 4 (Step S503).

[0174] In this step, the file entry is recorded from LBN=170 byreferring to the leading location LBN of the file entry area in themanagement area of the AVFILES.IFO and similarly the file attributeinformation is recorded from LBN=87 by referring to the leading locationLBN of the file attribute information area.

[0175] In this step, the recording of the file attribute information andthe file entry changes the size of the extent of the directory AV_DIR1and the size of the AVFILES.IFO file. Therefore, based on such a change,an allocation descriptor of the file entry of the directory AV_DIR1 andthe file entry of the AVFILES.IFO file are rewritten.

[0176] Next, by scanning the space bitmap on the memory unit 4, thepresence or absence of contiguous unrecorded logical blocks and in anumber required for recording the AV file is judged (Step S504). Ifjudged as the absence of contiguous unrecorded logical blocks and in therequired number (Step S504: No), then error handling is carried out andthe AV file recording process is completed. If judged as the presence,data is recorded with respect to the logical blocks on the disc, whichcorrespond to the not recorded area obtained in the Step S504 (StepS505).

[0177] When the recording of the AV file data is completed, informationconcerning the location and the length of the extent of the AV file isrecorded in the allocation descriptor in the file entry on the memoryunit 4, which was created in Step S503, so as to update the filemanagement information of the AV file (Step S506).

[0178] Next, the bits of the space bitmap on the memory unit 4corresponding to the logical blocks onto which data was recorded in StepS504 are changed to “0”, which represents an “allocated” state (StepS507). Then, contents of the memory unit 4 are written back to thelocation at LBN=0 to 250 (Step S508). In this way, the file is recorded,which means that the AV file is recorded under the directory AV_DIR1.The partition space after recording of the AV file becomes a structureshown in FIG. 10.

[0179] As stated above, according to Embodiment 6, the management areais divided into plural areas, at least one of the divided managementareas is allocated to a file entry, and at least one of them isallocated to a file attribute information. Thereby, a location forwriting at the time of starting recording can be judged easily, so thatan unnecessary seek operation can be avoided at the time of recording anAV file.

[0180] Embodiment 7

[0181] The following describes a file management method according toEmbodiment 7 of the present invention, with reference to the drawings. Aconfiguration example of a data recording/reproducing apparatus to whichthe file management method according to Embodiment 7 of the presentinvention is applied is illustrated in FIG. 1, as in the case withEmbodiment 1. Operations of recording and reproducing data also aresimilar to Embodiment 1.

[0182]FIG. 11 shows an example of a file/directory structure immediatelyafter creating a directory for recording an AV file in the filemanagement method according to Embodiment 7. In FIG. 11, ROOT surroundedby an oval denotes a root directory, AV_DIR11, AV_DIR21, AV_DIR31 andAV_DIR41 denote directories for recording an AV file therein, andAVFILES.IFO denotes a management file created in the directory AV_IFO.

[0183]FIG. 12 shows a data structure in the partition space in a statewhere the file/directory structure shown in FIG. 11 is recorded on adisc to which the file management method according to Embodiment 7 isapplied.

[0184] In FIG. 12, at LBN=0 to 93, a space bitmap descriptor isrecorded. As described later, since LBN=384+A*4+1 or later becomes anunallocated state, each bit corresponding to these sectors is set at“1”.

[0185] At LBN=94, a file set descriptor is recorded. In the case of afile entry of the root directory, its location information is recordedin the file set descriptor.

[0186] At LBN=95, a terminating descriptor is recorded. At LBN=96, thefile entry of the ROOT directory is recorded.

[0187] At LBN=97 to 127, a file identifier descriptor of the ROOTdirectory as a parent directory and a file identifier descriptor of thedirectory AV_DIR1 are recorded.

[0188] At LBN=128, a file entry of the directory AV_DIR1 is recorded. AtLBN=129 to 159, a file identifier descriptor of the directory AV_DIR1 asa parent directory and a file identifier descriptor of each of thedirectories including AV_IFO, AV_DIR11, AV_DIR21, AV_DIR31 and AV_DIR41are recorded.

[0189] At LBN=160, a file entry of the directory AV_IFO is recorded. AtLBN=161 to 191, a file identifier descriptor of the directory AV_IFO asa parent directory and a file identifier descriptor of the fileAVFILES.IFO are recorded.

[0190] At LBN=192, a file entry of the file AVFILES.IFO is recorded. AtLBN=193 to 223, the file AVFILES.IFO is recorded.

[0191] At LBN=224, a file entry of the directory AV_DIR11 is recorded.At LBN=225 to 231, a file identifier descriptor of the directoryAV_DIR11 as a parent directory is recorded. Hereinafter, LBN=224 to 231will be made a directory block of the directory AV_DIR11.

[0192] At LBN=232 to 255, an extent of the file AVFILES.IFO is recorded.As for this extent, the value of the upper 2 bits of the allocationdescriptor is set so that the extent becomes “allocated” and “notrecorded”. Therefore, in the operation of the conventional file system,data cannot be written at LBN=232 to 255.

[0193] When recording on the disc the AV_FILE11 as an AV file so as tobe under the directory AV_DIR11 as illustrated in FIG. 13, the fileidentifier descriptor of the AV_FILE11 file is added at LBN=225 to 231,the file entry of the file AV_FILE11 is recorded at a logical block ofLBN=384+A*4+1, which corresponds to an unallocated area, and data of theAV_FILE11 is recorded at LBN=384+A*4+2 or later. After this, recordingis continued using similar procedures.

[0194] As stated above, according to Embodiment 7, a file entryindicating the specific directory and a file identifier descriptorindicating a specific directory are recorded together at a predeterminedlocation. Thereby, the number of seek operations can be reduced in theprocess of adding and rewriting a file in the specific directory, sothat recording and reproducing of a file having a real time propertysuch as an AV file can be conducted easily.

[0195] Embodiment 8

[0196] The following describes a file management method according toEmbodiment 8 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 8 of the present invention is applied is illustrated in FIG.12.

[0197] At LBN=224, a file entry of the directory AV_DIR11 is recorded.At LBN=225 to 231, a file identifier descriptor of the directoryAV_DIR11 as a parent directory is recorded. Hereafter, LBN=224 to 231will be made a directory block of the directory AV_DIR11.

[0198] LBN=232 to 255 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=232 to 255.

[0199] Similarly, LBN=384 to 384+A also is an extent of the AVFILES.IFOfile, and the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=384 to 384+A. This area is reserved for a file entrycreated in the directory AV_DIR11.

[0200] When recording on the disc the AV_FILE11 as an AV file so as tobe under the directory AV_DIR11, the file identifier descriptor of theAV_FILE11 file is added at LBN=225 to 231, the file entry and the fileattribute information of the file AV_FILE11 are recorded at the area ofLBN=384 to 384+A, which is reserved for the AV_DIR11, and data of theAV_FILE11 is recorded at LBN=384+A*4+1 or later, which is a logicalblock of the disc corresponding to an unallocated area. After this,recording is continued using similar procedures.

[0201] As stated above, according to Embodiment 8, not only are a fileentry indicating a specific directory and a file identifier descriptorindicating the specific directory recorded together at a predeterminedlocation but also a file entry and file attribute information of a filein the specific directory are recorded together. Thereby, the number ofseek operations can be reduced further compared with Embodiment 7, sothat recording and reproducing of a file having a real time propertysuch as an AV file can be conducted more easily.

[0202] Embodiment 9

[0203] The following describes a file management method according toEmbodiment 9 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 9 of the present invention is applied is illustrated in FIG.12.

[0204] At LBN=224, a file entry of the directory AV_DIR11 is recorded.At LBN=225 to 231, a file identifier descriptor of the directoryAV_DIR11 as a parent directory is recorded. Hereafter, LBN=224 to 231will be made a directory block of the directory AV_DIR11.

[0205] LBN=232 to 255 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=232 to 255.

[0206] Hereafter, LBN=224 to 255 will be made a directory block groupfor recording videos.

[0207] At LBN=256, a file entry of the directory AV_DIR21 is recorded.At LBN=257 to 263, a file identifier descriptor of the directoryAV_DIR21 as a parent directory is recorded. Hereafter, LBN=256 to 263will be made a directory block of the directory AV_DIR21.

[0208] LBN=264 to 287 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=264 to 287. Hereafter, LBN=256 to 287 will be made adirectory block group for recording audio.

[0209] At LBN=288, a file entry of the directory AV_DIR31 is recorded.At LBN=289 to 295, a file identifier descriptor of the directoryAV_DIR21 as a parent directory is recorded. Hereafter, LBN=288 to 295will be made a directory block of the directory AV_DIR31.

[0210] LBN=296 to 319 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=231 to 255. Hereafter, LBN=288 to 319 will be made adirectory block group for recording still pictures.

[0211] At LBN=320, a file entry of the directory AV_DIR41 is recorded.At LBN=321 to 327, a file identifier descriptor of the directoryAV_DIR41 as a parent directory is recorded. Hereafter, LBN=320 to 327will be made a directory block of the directory AV_DIR41.

[0212] LBN=328 to 351 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=231 to 255. Hereafter, LBN=288 to 319 will be made adirectory block group for recording data other than an AV file.

[0213] When recording on the disc a Video_FILE11 as a video file so asto be under the directory AV_DIR11, as shown in FIG. 14, a fileidentifier descriptor of the file Video_FILE11 is added at LBN=225 to231, a file entry of the file Video_FILE11 is recorded at LBN=Z+1, whichis located at LBN=384+A*4+1 or later as a logical block of the disccorresponding to an unallocated area, and data of the file Video_FILE11is recorded at LBN=Z+2 to V.

[0214] Next, when recording an Audio_FILE21 as an audio file under thedirectory AV_DIR21 also, as shown in FIG. 14, a file identifierdescriptor of the file Audio_FILE21 is added at LBN=257 to 263, a fileentry of the file Audio_FILE21 is recorded at LBN=V+1, which is alogical block of the disc corresponding to an unallocated area, and dataof the file Audio_FILE21 is recorded at LBN=V+2 to W.

[0215] Further, when recording a Photo_FILE31 as a still picture fileunder the directory AV_DIR31, a file identifier descriptor of the filePhoto_FILE31 is added at LBN=289 to 295, a file entry of the filePhoto_FILE31 is recorded at LBN=W+1, which is a logical block of thedisc corresponding to an unallocated area, and data of the filePhoto_FILE31 is recorded at LBN=W+2 to X.

[0216] Finally, when recording an Other_FILE41 as a file other than anAV file under the directory AV_DIR41, a file identifier descriptor ofthe file Other_FILE41 is added at LBN=321 to 327, a file entry of thefile Other_FILE41 is recorded at LBN=X+1, which is a logical block ofthe disc corresponding to an unallocated area, and data of the fileOther_FILE41 is recorded at LBN=X+2 to Y. After this, recording iscontinued using similar procedures.

[0217] As stated above, according to Embodiment 9, a file is classifiedaccording to a prescribed specification such as video and audio, and afile entry and a file identifier descriptor of such a file are recordedat a predetermined location, whereby a seek operation can be reduced toa minimum.

[0218] Embodiment 10

[0219] The following describes a file management method according toEmbodiment 10 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 10 of the present invention is applied is illustrated in FIG.12.

[0220] In FIG. 12, LBN=384 to 384+A is an extent of the fileAVFILES.IFO. As for this extent, the value of the upper 2 bits of theallocation descriptor is set so that the extent becomes “allocated” and“not recorded”. Therefore, in the operation of the conventional filesystem, data cannot be written at LBN=384 to 384+A. This area isreserved for a file entry that will be created in the directoryAV_DIR11.

[0221] LBN=384+A+1 to 384+A*2 is an extent of the file AVFILES.IFO. Asfor this extent, the value of the upper 2 bits of the allocationdescriptor is set so that the extent becomes “allocated” and “notrecorded”. Therefore, in the operation of the conventional file system,data cannot be written at LBN=384+A+1 to 384+A*2. This area is reservedfor a file entry that will be created in the directory AV_DIR21.

[0222] Similarly, LBN=384+A*2+1 to 384+A*3 is an extent of the fileAVFILES.IFO. As for this extent, the value of the upper 2 bits of theallocation descriptor is set so that the extent becomes “allocated” and“not recorded”. Therefore, in the operation of the conventional filesystem, data cannot be written at 384+A*2+1 to 384+A*3. This area isreserved for a file entry that will be created in the directoryAV_DIR31.

[0223] Similarly, LBN=384+A*3+1 to 384+A*4 is an extent of the fileAVFILES.IFO. As for this extent, the value of the upper 2 bits of theallocation descriptor is set so that the extent becomes “allocated” and“not recorded”. Therefore, in the operation of the conventional filesystem, data cannot be written at 384+A*3+1 to 384+A*4. This area isreserved for a file entry that will be created in the directoryAV_DIR41.

[0224] When recording on the disc a Video_FILE11 as a video file so asto be under the directory AV_DIR11, as shown in FIG. 15, a fileidentifier descriptor of the file Video_FILE11 is added at LBN=225 to231, a file entry and file attribute information of the fileVideo_FILE11 are recorded at an area of LBN=384 to 384+A, which isreserved for the AV_DIR11, and data of the file Video_FILE11 is recordedat LBN=Z+1 to V, which is located at LBN=384+A*4+1 or later as a logicalblock of the disc corresponding to an unallocated area.

[0225] Next, when recording an Audio_FILE21 as an audio file under thedirectory AV_DIR21 also, as shown in FIG. 15, a file identifierdescriptor of the file Audio_FILE21 is added at LBN=225 to 231, a fileentry and file attribute information of the file Audio_FILE21 arerecorded at LBN=384+A+1 to 384+A*2, which is reserved for the AV_DIR21,and data of the file Audio_FILE21 is recorded at LBN=V+1 to W as a notrecorded area.

[0226] Further, when recording a Photo_FILE31 as a still picture fileunder the directory AV_DIR31 also, as shown in FIG. 15, a fileidentifier descriptor of the file Photo_FILE31 is added at LBN=289 to295, a file entry and file attribute information of the filePhoto_FILE31 are recorded at LBN=384+A*2+1 to 384+A*3, which is reservedfor the AV_DIR31, and data of the file Photo_FILE31 is recorded atLBN=W+1 to X as a not recorded area.

[0227] Finally, when recording an Other_FILE41 as a file other than anAV file under the directory AV_DIR41 also, as shown in FIG. 15, a fileidentifier descriptor of the file Other_FILE41 is added at LBN=321 to327, a file entry and file attribute information of the fileOther_FILE41 are recorded at LBN=384+A*3+1 to 384+A*4, which is reservedfor the AV_DIR41, and data of the file Other_FILE41 is recorded atLBN=X+1 to Y as a not recorded area.

[0228] As stated above, according to Embodiment 10, not only a file isclassified according to a prescribed specification such as video andaudio and a file entry and a file identifier descriptor of such a fileis recorded together at a predetermined location, but also a file entryand file attribute information of a file in a specific directory arebrought together, whereby while suppressing seek operation, a proceduresuch as adding and rewriting of a file in the specific directory can beconducted.

[0229] Embodiment 11

[0230] The following describes a file management method according toEmbodiment 11 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 11 of the present invention is applied is illustrated in FIG.12.

[0231] LBN=352 to 383 is an extent of the file AVFILES.IFO. As for thisextent, the value of the upper 2 bits of the allocation descriptor isset so that the extent becomes “allocated” and “not recorded”.Therefore, in the operation of the conventional file system, data cannotbe written at LBN=384 to 384+A.

[0232] This area is reserved for creating a new file identifierdescriptor, when an area of the directory block group, which has beenreserved already at LBN=224 to 351, is exhausted.

[0233] As stated above, according to Embodiment 11, an area of thedirectory block group which should be reserved additionally is reservedat a predetermined location, which can suppress a seek operation on thedisc, while enables a procedure such as adding and rewriting of a filein a specific directory.

[0234] Embodiment 12

[0235] The following describes a file management method according toEmbodiment 12 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 12 of the present invention is applied is illustrated in FIG.12.

[0236] In Embodiment 8, when recording an AV file under the directoryAV_DIR11, a file identifier descriptor of the file to be recorded isadded at LBN=225 to 231, and at the same time a file entry and fileattribute information of the file to be recorded are recorded at LBN=384to 384+A, which is reserved for the directory AV_DIR11. However, thefollowing case might be considered: that is, when an A-th file AV_FILE_Ais recorded and a file identifier descriptor of the AV_FILE_A and a fileentry and file attribute information of the AV_FILE_A are recorded, anarea for recording a new file identifier descriptor or a new file entryand file attribute information might become insufficient in thedirectory block of the directory AV_DIR11.

[0237] In this case, when attempting to add a file AV_FILE_A+1 further,a new directory AV_DIR12 is created as shown in FIG. 16. Then, LBN=232and LBN=233 to 239 are reserved as a directory block for recording afile entry of the directory AV_DIR12 and a file identifier descriptor ofthe directory AV_DIR12, respectively, so as to follow the directoryblock for recording of the file identifier descriptor of the directorAV_DIR11 reserved at an area of LBN=224 to 231.

[0238] At the same time, an area of LBN=383+A*4+1 to 383+A*5 is reservedfor recording a file entry and file attribute information of theAV_DIR12 in the same manner as in the area at LBN=384 to 384+A reservedfor recording the file entry and file attribute information of the filefor the directory AV_DIR11.

[0239] In a like manner as in the foregoing, a file identifierdescriptor, a file entry and file attribute information of the fileAV_FILE_A+1 are recorded as the A+1-th file at each of the reservedareas. In addition, data of the file AV_FILE_A+1 is recorded at LBN=X+1to Y as a logical block on the disc corresponding to an unallocatedarea.

[0240] Similarly after this, recording is carried out so that adirectory AV_DIR13 is added from the A*2+1-th file and a directoryAV_DIR14 is added from the A*3+1-th file, until the capacity of thedirectory block group is exhausted.

[0241] As stated above, according to Embodiment 12, even when anoperation such as adding a new file is performed in the case of theabsence of a sufficient not-registered area for recording, a seekoperation can be reduced to a minimum.

[0242] Embodiment 13

[0243] The following describes a file management method according toEmbodiment 13 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 13 of the present invention is applied is illustrated in FIG.12.

[0244] When recording is continued by the method described in Embodiment12, in the case of recording an AV file under the directory AV_DIR14, afile identifier descriptor of the file to be recorded is added atLBN=249 to 255, and at the same time a file entry and file attributeinformation of the file to be recorded are recorded at LBN=383+A*6+1 to383+A*7 reserved for the directory AV_DIR14, as shown in FIG. 17.However, when the A*4-th file AV_FILE_A*4 is recorded and a fileidentifier descriptor of the AV_FILE_A*4 and a file entry and fileattribute information of the AV_FILE_A*4 are recorded, then an area forrecording a new file identifier descriptor, or a new file entry and fileattribute information might become lost in a directory block of thedirectory AV_DIR14.

[0245] In this case, when attempting to add a file AV_FILE_A*4+1further, in spite of the intention of creating a directory AV_DIR15 inthe directory block group by the method described in Embodiment 12, anarea for adding a file identifier descriptor cannot be reserved becausethe directory block group has been exhausted already.

[0246] Then, as shown in FIG. 18, a new directory block group is createdin the reserved area at LBN=352 to 383, which is reserved in Embodiment11, and the directory AV_DIR15 is created therein. Thereby, LBN=352 andLBN=353 to 359 are reserved as a directory block for recording a fileentry of the directory AV_DIR15 and a file identifier descriptor of thedirectory AV_DIR15, respectively.

[0247] At the same time, in a like manner as the area reserved atLBN=383+A*6+1 to 383+A*7 for recording the file entry and file attributeinformation of the file for the directory AV_DIR14, an area ofLBN=383+A*7+1 to 383+A*8 is reserved for recording a file entry and fileattribute information of the directory AV_DIR15.

[0248] With this method, a file identifier descriptor, a file entry andfile attribute information can be recorded at each of the reserved areasas the A*4+1-th file in a similar manner as in the foregoing. Inaddition, data of the AV_FILE_A*4+1 is recorded at LBN=X+1 to Y as alogical block on the disc corresponding to an unallocated area. Afterthis, recording is continued by a similar procedure.

[0249] Further, in the case of the absence of an area for recording anew file identifier descriptor or a new file entry and file attributeinformation in the directory block in the directory AV_DIR15 when theA*5-th file AV_FILE_A*5 is recorded, recording is carried out in a likemanner described in Embodiment 12 so that a directory AV_DIR16 is addedfrom the A*5+1-th file and a directory AV_DIR17 is added from theA*6+1-th file, until the capacity of the directory block group isexhausted.

[0250] As stated above, according to Embodiment 13, when a file entry orthe like is recorded by classifying it according to a prescribedspecification, and even when a sufficient not-registered area forrecording is exhausted and a procedure such as adding a new file isconducted, a seek operation can be reduced to a minimum.

[0251] Embodiment 14

[0252] The following describes a file management method according toEmbodiment 14 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 14 of the present invention is applied is illustrated in FIG.12.

[0253] When recording is continued by the method described in Embodiment13, in the case of recording an AV file under the directory AV_DIR18 asshown in FIG. 19, a file identifier descriptor of the file to berecorded is added at LBN=377 to 383, and at the same time a file entryand file attribute information of the file to be recorded are recordedat LBN=383+A*10+1 to 383+A*11, which is reserved for the directoryAV_DIR18. However, when the A*8-th file AV_FILE_A*8 is recorded and afile identifier descriptor of the AV_FILE_A*8 and a file entry and fileattribute information of the AV_FILE_A*8 are recorded, then an area forrecording a new file identifier descriptor, or a new file entry and fileattribute information might become insufficient in a directory block ofthe directory AV_DIR18.

[0254] In this case, when attempting to add a file AV_FILE_A*8+1further, in spite of the intention of creating a directory AV_DIR19 inthe directory block group by the method described in Embodiment 12, anarea for adding a file identifier descriptor cannot be reserved becausethe directory block group has been exhausted already. In addition,although it can be considered that the directory block reserved anddesignated by the method described in Embodiment 11 is used, such anarea has been used already, so that there is no area for adding.

[0255] In this case, as shown in FIG. 20, at the initially reserved andthe remaining LBN=384+A*11+1 to Z in the area reserved for a file entryand file attribute information conventionally, a new directory blockgroup is created, and a directory AV_DIR19 is created in the directoryblock group. Then, LBN=384+A*11+1 and LBN=384+A*11+2 to 384+A*11+8 arereserved as a directory block for recording a file entry of thedirectory AV_DIR19 and a file identifier descriptor of the directoryAV_DIR19, respectively.

[0256] At the same time, in a like manner as the area reserved at thearea of LBN=384+A*10+1 to 384+A*11 for recording the file entry and fileattribute information of the file for the directory AV_DIR18, an area ofLBN=383+A*11+33 to 384+A*12+32 is reserved for recording a file entryand file attribute information of the directory AV_DIR19.

[0257] Then, a file identifier descriptor, a file entry and fileattribute information are recorded at each of the reserved areas as theA*8+1-th file in a similar manner as in the foregoing. In addition, dataof the AV_FILE_A*8+1 is recorded at LBN=X+1 or later as a logical blockon the disc corresponding to an unallocated area. After this, recordingis continued by a similar procedure.

[0258] Further, in the case of the absence of an area for recording anew file identifier descriptor or a new file entry and file attributeinformation in the directory block in the directory AV_DIR15 when theA*9-th file AV_FILE_A*9 is recorded, recording is carried out in a likemanner described in Embodiment 12 so that a directory AV_DIR110 is addedfrom the A*9+1-th file and a directory AV_DIR111 is added from theA*10+1-th file, until the capacity of the directory block group isexhausted.

[0259] As stated above, according to Embodiment 14, a reserved area isused effectively, so that even when there is no sufficientnot-registered area for recording and an operation such as adding a newfile is conducted, a seek operation can be reduced to a minimum.

[0260] Embodiment 15

[0261] The following describes a file management method according toEmbodiment 15 of the present invention, with reference to the drawings.As in the case of Embodiment 7, a data structure of the partition spacein a state where the file/directory structure shown in FIG. 11 isrecorded on a disc to which the file management method according toEmbodiment 15 of the present invention is applied is illustrated in FIG.12.

[0262] When recording is continued by the method described in Embodiment13, in the case of recording an AV file under the directory AV_DIR18 asshown in FIG. 21, a file identifier descriptor of the file to berecorded is added at LBN=384+A*11+26 to 384+A*11+32, and at the sametime a file entry and file attribute information of the file to berecorded are recorded at an area of LBN=384+A*14+33 to Z, which isreserved for the directory AV_DIR14. However, when the A*12-th fileAV_FILE_A*12 is recorded and a file identifier descriptor of theAV_FILE_A*12 and a file entry and file attribute information of theAV_FILE_A*12 are recorded, then an area for recording a new fileidentifier descriptor, or a new file entry and file attributeinformation might become insufficient in a directory block of thedirectory AV_DIR18.

[0263] In this case, when attempting to add a file AV_FILE_A*12+1further, in spite of the intention of creating a directory AV_DIR113 inthe directory block group by the method described in Embodiment 12, anarea for adding a file identifier descriptor cannot be reserved becausethe directory block group has been exhausted already.

[0264] In addition, in spite of the intention of using the directoryblock reserved and designated by the method described in Embodiment 11according to the method described in Embodiment 13, such an area alsohas been used already, so that there is no area for adding. Furthermore,in spite of the intention of reserving a new directory block group inthe reserved area by the method described in Embodiment 14, in the caseof exhausting the reserved area until LBN=Z, which is reserved for afile entry and file attribute information conventionally, there is noarea for adding in the reserved area.

[0265] In this case, as shown in FIG. 22, in the remaining LBN=Y+1 toLast LBN in an unallocated area in which an entity of a file isrecorded, a reserved area like the reserved area created at the time ofcreation of the initial partition space is reserved newly at LBN=Y+1 toZZ. Then, a directory block group is created in the newly reserved area,and the directory AV_DIR113 is created in the directory block group.LBN=X+1 and LBN=X+2 to X+8 are reserved as a directory block forrecording a file entry of the directory AV_DIR113 and a file identifierdescriptor of the directory AV_DIR113, respectively.

[0266] At the same time, in a like manner as the area reserved at thearea of LBN=Y+1 to Y+A for recording the file entry and file attributeinformation of the file for the directory AV_DIR113, an area ofLBN=384+A*11+33 to 384+A*12+32 is reserved for recording a file entryand file attribute information of the directory AV_DIR113.

[0267] Then, a file identifier descriptor, a file entry and fileattribute information are recorded at each of the reserved areas as theA*12+1-th file in a similar manner as in the foregoing. In addition,data of the AV_FILE_A*12+1 is recorded at LBN=X+1 or later as a logicalblock on the disc corresponding to an unallocated area. After this,recording is continued by a similar procedure.

[0268] Further, in the case of the absence of an area for recording anew file identifier descriptor or a new file entry and file attributeinformation in the directory block in the directory AV_DIR113 when theA*12-th file AV_FILE_A*12 is recorded, recording is carried out in alike manner described in Embodiment 12 so that a directory AV_DIR114 isadded from the A*12+1-th file and a directory AV_DIR115 is added fromthe A*13+1-th file, until the capacity of the directory block group isexhausted.

[0269] As stated above, according to Embodiment 15, even when there isno space area in the reserved area, and when there is no sufficientnot-registered area for recording and a procedure such as adding a newfile is conducted, a seek operation can be reduced to a minimum byutilizing the space area of the disc.

INDUSTRIAL APPLICABILITY

[0270] As stated above, according to the file management methods of thepresent invention, file management information and attribute informationon an AV file are recorded at a contiguous area reserved in advance,whereby a seek operation with respect to a disc can be reduced, andtherefore real-time recording/reproducing of the AV file can berealized.

1. A file management method that has file management information formanaging contiguous blocks on a disc as an extent and for grouping theextent as a file and managing the file, comprising: when creating a newdirectory on the disc, reserving as a reserved area for recording filemanagement information on the file a file or a data area in thedirectory; and recording information concerning an operation conditionof the file management information in the reserved area, in addition tomanagement information on the directory and the file.
 2. The filemanagement method according to claim 1, wherein when the file managementinformation recorded in the reserved area is updated, informationindicating a fact that the file management information has been updatedis recorded in the reserved area.
 3. The file management methodaccording to claim 1, wherein a leading location block and an endinglocation block of the reserved area on the disc are recorded in thereserved area.
 4. The file management method according to claim 1,wherein a leading location block of an area for a file entry in thereserved area and a leading location block of an area for file attributeinformation in the reserved area are recorded in the reserved area. 5.The file management method according to claim 1, wherein a time when thefile management information is last updated is recorded in the reservedarea.
 6. The file management method according to claim 1, wherein thereserved area is divided into N areas (N is a natural number no lessthan 2), at least one of the divided areas is allocated to an area for afile entry, and at least one of the divided areas is allocated to anarea for file attribute information.
 7. A file management method thathas file management information for managing contiguous blocks on a discas an extent and for grouping the extent as a file and managing thefile, comprising: when creating a new directory on the disc, reservingas a reserved area for recording file management information on the filea file or a data area in the directory; and reserving a directory blockhaving a predetermined size in the reserved area for recording a fileentry of the directory and a file identifier descriptor of thedirectory.
 8. The file management method according to claim 7, whereinan area is reserved as a directory block group in a size of an arbitraryintegral multiple of a size of the directory block.
 9. The filemanagement method according to claim 8, wherein the size of thedirectory block group is in the unit of error correction.
 10. The filemanagement method according to claim 8, wherein concurrently with theprocess of reserving the directory block group, an area for recordingfor a file entry, which corresponds to a required area for recording thefile whose file identifier descriptor can be described in the directory,and a part or all of the file is reserved in the reserved area initiallyand at one time.
 11. The file management method according to claim 8,wherein an area is reserved as a directory area in a size of anarbitrary integral multiple of a size of the directory block group. 12.The file management method according to claim 10, wherein concurrentlywith the process of reserving the directory area, an area for recordingfor a file entry, which corresponds to a required area for recording thefile whose file identifier descriptor can be described in the directory,and a part or all of the file is reserved in the reserved area initiallyand at one time.
 13. The file management method according to 10, whereinat the same time an area corresponding to the directory block group isreserved beforehand.
 14. The file management method according to claim11, wherein when creating a new file, the directory block is creatednewly at the end of the reserved directory block.
 15. The filemanagement method according to claim 11, wherein when, in the reserveddirectory block group, any one of the area for information concerningthe file identifier descriptor in the directory and the reserved areafor recording the file entry and the part or all of the file becomesinsufficient and when a new file further is created, the directory blockis created newly at the end of the reserved directory block, and at thesame time an area for recording for a file entry, which corresponds to arequired area for recording the file whose file identifier descriptorcan be described in the directory, and a part or all of the file isreserved in the reserved area at one time.
 16. The file managementmethod according to claim 12, wherein when creating a new file, thedirectory block group is created newly at the area reserved beforehandas the directory block group.
 17. The file management method accordingto claim 12, wherein when, in the reserved directory block group, anyone of the area for information concerning the file identifierdescriptor in the directory and the reserved area for recording the fileentry and the part or all of the file becomes insufficient and when anew file further is created, the directory block group is created newlyat the area reserved beforehand as the directory block group, and at thesame time an area for recording for a file entry, which corresponds to arequired area for recording the file whose file identifier descriptorcan be described in the directory, and a part or all of the file isreserved in the reserved area at one time.
 18. The file managementmethod according to claim 12, wherein when creating a new file, thedirectory block group is created newly in the reserved area.
 19. Thefile management method according to claim 12, wherein when, in thereserved directory block group, any one of the area for informationconcerning the file identifier descriptor in the directory and thereserved area for recording the file entry and the part or all of thefile becomes insufficient, the area reserved beforehand as the directoryblock group also becomes insufficient, and when a new file is created,the directory block group is created newly in the reserved area, and atthe same time an area for recording for a file entry, which correspondsto a required area for recording the file whose file identifierdescriptor can be described in the directory, and a part or all of thefile is reserved in the reserved area at one time.
 20. The filemanagement method according to claim 12, wherein when creating a newfile, the reserved area is reserved newly in a space area of the disc,and the directory block group is created in the thus prepared reservedarea.
 21. The file management method according to claim 12, wherein,when, in the reserved directory block group, the area for recording thefile identifier descriptor in the directory becomes insufficient, thearea reserved beforehand as the directory block become insufficient, andan area for reservation is insufficient in the reserved area that hasbeen reserved initially, and when a new file is created, the reservedarea is reserved newly in a space area of the disc, the directory blockgroup is created in the thus prepared reserved area, and at the sametime an area for recording for a file entry, which corresponds to arequired area for recording the file whose file identifier descriptorcan be described in the directory, and a part or all of the file isreserved in the thus prepared reserved area at one time.
 22. A datarecording apparatus using the file management method according to anyone of claims 1 to
 21. 23. A data reproducing apparatus using the filemanagement method according to any one of claims 1 to
 21. 24. A datarecording/reproducing apparatus using the file management methodaccording to any one of claims 1 to
 21. 25. A disc subjected torecording by any one of the data recording apparatus according to claim22 and the data recording/reproducing apparatus according to claim 24.